A discharge is generated within a discharge vessel. The discharge vessel has a dielectric layer disposed between at least one electrode and the discharge, and for this reason this type of discharge is also known as a silent, or quiet or dielectrically impaired discharge, or barrier discharge. Incoherently emitting radiation sources include ultraviolet (UV) and infrared (IR) radiators, as well as discharge lamps that in particular radiate visible light. The invention is suitable for both low-pressure and high-pressure gas fillings and for all gas pressures that are in the range between low and high pressure.
The excitation of such discharges is typically done with the aid of an alternating current, as disclosed for instance in the German Patent Disclosures DE 40 22 279 , Eliasson et al., and DE 42 03 594, Kim and in U.S. Pat. No. 5,117,160, Konda et al. The excitation frequency there is selected within the range between the frequency of the commercial-technical alternating current and several megahertz (DE 40 22 279), or between 20 and 100 kHz (U.S. Pat. No. 5,117,160).
The disadvantage of this mode of operation is that the desired radiation yields are relatively low, at technologically relevant power densities. Typical UV efficiencies are between 10%, for surface power densities of 1 kW/m.sup.2 and 15% at 10 W/m.sup.2 ; see "3. Tagung des Arbeitskreises UV und IR am Lichttechnischen Institut der Universitat Karlsruhe" ["3rd Conference of the UV and IR Study Group at the Light Technology Institute, University of Karlsruhe"] on Oct. 7, 1992, and "Dielectric Barrier Discharges: An Unusual Light Source", M. Neiger, LTI, University of Karlsruhe, Sixth International Symposium on the Science and Technology of Light Sources, Budapest, 1992.